Tag: cancer

As a sugar-rich foodstuff, jelly is not often seen as a good thing for diabetics. But a new gel-based method for administering drugs could cut back on injections for diabetics and virtually eliminate their blood sugar highs and lows. Scientists have come up with a new gelatinous drug form that releases a slow but regular dose of an insulin-regulating hormone. In mice, it kept glucose levels down for five straight days—120 times longer than the hormone alone. And the method could be used to deliver drugs to treat cancer and other diseases as well.

Peptide drugs are an up-and-coming method used to treat a number of diseases. There are currently 40 peptide drugs on the market, and 650 more are being clinically tested, so the pharmaceutical industry is investing a lot in the future of these treatments. One peptide drug, used to treat diabetes, relies on weekly injections of tiny plastic capsules filled with the peptide that causes insulin to be released slowly over the course of the week. This means far fewer injections than diabetics’ typical insulin regimen, but the injections are painful due to the large needles required to fit the capsules. Side effects like nausea are common. Plus the production is complicated because the drug and its capsule must be synthesized separately and then combined.

The quadruple helix structure is shown at the left. Fluorescent markers on the right show where the helix appears on an individual chromosome (top) and in cells (bottom).

What does DNA look like? According to the biology textbooks of the last half century, it consists of a twisting ladder of base pairs: A with T and C with G. But a new study in Nature presents evidence that some human DNA may actually have four strands instead of two, and researchers say the quadruple helix may be linked to cancer.

The now-ubiquitous double-helix structure was first published in the journal Nature in 1953 by scientists James Watson and Francis Crick from the University of Cambridge. Nearly 60 years later, scientists from the same institution have published a paper in the same journal, but their results suggest that there may be more to the structure of DNA than their predecessors thought.

Naked mole rats are well-known wunderkind around here—numerous studies have revealed that the weird subterranean critters don’t feel pain from acid, are massively long-lived for rodents, and don’t seem to get cancer. But an evolutionarily distant relative, the blind mole rat, also has a few tricks up its, er, sleeves: It shares the naked mole rats’ resistance to cancer, but through a completely different mechanism. Now a study in the Proceedings of the National Academy of Sciences helps explain what’s protecting them.

On this date in 1957, five Air Force volunteers and one photographer stood next to a sign labeled “Ground Zero. Population: 5” and watched a two-kiloton nuclear bomb explode 18,500 feet over their heads. (The height listed at the beginning of the video is incorrect.) Before the dangers of radiation exposure were fully understood, the government undertook many such tests to determine the effects of atomic weapons. This particular trial was an attempt to prove that exploding nuclear missiles in the atmosphere could be relatively safe. While the men in this video were not greatly affected by the blast—at least three, including the cameraman, lived past age 80—many other people exposed to fallout from nuclear tests developed cancer. Check out the full story behind the video at NPR.

In the presence of ultraviolet light, the nanoparticle
shrinks from 150 to 40 nanometers.

As anyone who has played with a powerful laser or just suffered a bad sunburn can attest, light has an impressive power to physically change objects. And now we know that light can make nanoparticles expand and contract like miniature Hoberman Spheres. MIT and Harvard researchers engineered nanoparticles that shrink to less than a third of their original size when exposed to ultraviolet rays; in the darkness or under visible light, they open back up to their more stable, larger size.

Nanoparticles have been touted as an effective way to deliver cancer-killing drugs straight to tumors without harming healthy cells in the process. But the structure of a tumor can block all but the smallest particles—those less than 100 nanometers (billionths of a meter)—from penetrating to the cancer’s heart. To deliver drugs to the entire tumor, the researchers suggest that the particles could be deployed while UV light keeps them in their smaller form, about 40 nanometers. Then, when the UV light is switched off, the particles will open to their full 150-nanometer size and release the drugs.

A new paper in The Lancet takes a look at the very best data on the prevalence of infection-caused cancers and comes up with some striking numbers. Overall, they estimate that 16% of cancer cases worldwide in 2008 had an infectious cause—2 million out of 12.7 million.

The nanoparticle. ACUPA is a protein that helps the particle attach to cancer
cells; the red and blue pieces are polymers that make up the particle’s shell.

One of the persistent problems in cancer treatments is that try as we might, it’s hard to get drugs to attack just tumors: they nearly always attack patients’ healthy cells too. Finding ways to get drugs to kill tumors, and tumors alone, is a major area of research, and a recent trial in Science Translational Medicine indicates that one promising strategy, encasing the drug in a tiny particle that dissolves when it reaches a tumor, works better than just using the drug alone.

Proton-beam therapy is massively expensive—$100+ million facilities, each treatment twice as much as radiation—and not proven to be any safer or more effective than other cancer treatments. So why are U.S. hospitals racing to build new proton-beam facilities?

Financial incentives, and the wrong ones, according to a skeptical piece at Bloomberg. To house the 200-ton cyclotron that accelerates protons to 93,000 miles per second, the facilities have to be as big as football fields, with 16-feet-thick concrete walls. Hospitals can afford to build them because proton-beam therapy is “extremely favorably reimbursed” by Medicare and many private insurance companies, says Sean Tunis, CEO of the Center for Medical Technology Policy. To foot the construction bill, hospitals will have to push the treatment aggressively to cancer patients.